Process of making printing-plates.



EMIL LEITNER, 0F HOBOKEN, NEW JERSEY, ASSIG-NOR T0 POWERS PHOTO-ENGRAVING COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW To all whomit may concern:

Be it known that I. 'EMIL LErrrIER, having declared my intention ofbecoming a citizen of the United States, residing at I-Ioboken, in thecounty-of Hudson and State of New Jersey, have invented certain new and.useful Im rovements in Processes of Making Printinglates, of which thefollowing is a specification.

The invention relates to the art of making half tone printing plates,and in certain of its aspects it is especially applicable to the makingof half tone copper printing plates.

Objects of the invention are to provide for artistic effects, andespecially artistic effects attainable only with the use of the brush,in the introduction of high lights or whites in the half tone plate; toprovide for rapid and inexpensive means for producing such artisticeffects to produce such and similar efiects without the use of engrayingor routing tools or machines; to produce such and similar effects incombined half tone and line plates.

Other objects of invention will in part appear hereinafter, and in partwill be obvious herefrom to those skilled in the art;

said objects being attained in the manner or by the steps set forthimthe appended claims.

The invention consists in the novel steps, combinations, processes andimprovements herein described.

In many classes of illustration Work, it is exceedingly desirable to getpure whites or high lights, which are not attainable by the half toneprocess alone. It has been customary in the art to use engraving tools,routing tools, and similar instruments to cut away or engrave parts of ahalf tone surface. Such tool work requires men of special skill,

and much time is consumed in thus working over the half tone plate tosecure effects of the character described. This consumes "a great dealof the time, making the process exceedingly lengthy, and the timeinvolved, the skilled operatives required, and the other attendantcauses very greatly increase the expense of producing such a printingplate,

- In addition to the foregoing, it is'ampossible by the use of tools toproduce the most artistic and desirable effects. The best ef fects arethose produced by the use of the brush, or rather where the effectobtained resembles brush work to a degree which it is impossible to'attain with either hand tools YORK- PBQCESS OF MAKING PRINTING-PLATES,

1 1 541343 Specification of Letters Patent.

No Drawing. Application filed January 26, 1914. Serial No. 814,534.

ther by photo-mechanical means entirely in conjunction with such use ofthe brush.

- The half tone plates may be produced in substantially the usualmanner, namely, by the making of the half tone negative from an or1g1nal'copy, of suitable character. The printing plate of metal, andpreferably of copper is then prepared to receive in a suitable manner alight sensitive solution. The sensitizing of the plate is preferablyeffected in accordance with what is known as the enamel face or enameltop method, which gives a-crisper and sharper plate.

The sensltlzlng solution is preferably French glue mixed with albuminand ammonlum bichromate, dissolved in water. This solution is usuallyflowed over the surface of the plate and spread in a uniform layer bycentrifugal action by whirling the plate, and subjecting it to heat todry the solution in a coating or layer upon the surface of the plate.The sensitized plate is subjected to the action of light through thehalf tone negative and the surface is then developed in water insubstantially the usual'manner.

which is likewise pigmentous thereby to guide the eye in applying themedium to get the desired effects and gradations in the va rious partsof the plate. As such a medium, by way of example, I employ gambogedissolved in water to a proper consistency to be applied by the brush. Iapply the gamboge solution in the desired manner, and at the desiredplaces in the printing plate, gradating same in a way which is onlypossible Patented Sept. 28, 1 915.

by the use of the brush. The gamboge solution is permitted to dry uponthe surface of the plate. The plate is then rolled up in any suitableink, such as an etching ink, over its entire surface, and this layerserves as a resist on the surface of the plate. The plate is thendampened, or immersed in water, and where the layer of ink rests uponthe gamboge it is removed by reason of the dissolution of the gambogetherebeneath.

Where the ink is directly adherent upon the surface of the plate it is,of course, not affected by the water. The surface of the plate iscompletely protected by the ink coating or layer over all parts of thedesign except where the amboge solution was ap-v plied, but where t egamboge solution was applied the surface 0 the plate is exposed. Theplate is now subjected to a deep etch, which cuts away the surface ofthe plate as exposed and in the required or desired degree of gradation.The surface of the plate is then cleansed from the 'ink in any suitablemanner, as by the application of turpentine or other suitable solvent,and by any other steps necessary or desirable to further cleanse thesurface. The plate isthen' etched in the usual or other suitable mannerto produce in the plate the half tone design, which in the case of acopper plate is usually done by an iron perchlorid solution.

The etching to produce the clear whites may occur subsequentto the halftone etchthe foregoing ing of the plate if desired, but it preferably isdone first, as the application of the ink or 'gamboge and thuseliminating from those parts the half tone dots or screen figures.

It will be understood from the foregoing that a process has beenprovided which realizes the advantages and objects of invention statedtogether with other objects and advantages, and that the delicate andartistic effects of brush work are realized by purely mechanical means,and at a small fraction of the expenditure of time and money requiredby'hand or other tool work, while efi'ecting results that are entirelyunattainable thereby. so

The invention, it will be understood, is not limited to the precisesteps or materials described but variations may be made-therefrom withinthe scope of the accompanying claims without departing from theprinciples of the invention.

What I do claim as my invention and desire'to'secure by Letters Patent,is:

1'. The process of making a printing plate which comprises sensitizingthe surface of the plate, exposing said surface to light action througha negative, developing said surface after it is exposed, applying toparts of said surface by means of a brush a medium soluble in a givensolvent, applying to said developed surface an acid .resist insoluble insaid solvent, applying said solvent to dissolve said soluble medium andto remove said resist where it overlies said medium to expose thesurface of the plate, deep etching said exposed portions of the plate,and further preparing said plate for printing.

2. The process of producing a printing plate which comprises sensitizingthe surface of the plate, exposing said surface to light action througha negative, developing said surface after it is exposed, a plying toparts of said surface by means 0 a brush a pigmentous medium soluble ina given solvent, applying to said developed surface an acid resistinsoluble in said solvent, applying said solvent to dissolve saidsoluble medium and to remove said resist where it overlies said solublemedium to expose the surface of the plate, deep etching said exposedportions of the plate, and further preparing said plate for printing.

3 The process of making a printing plate which comprises sensitizing thesurface of the plate, exposing said surface to light action through anegative, developing said surface after it is exposed, a plying to partsof said surface by means 0 a brush a medium soluble in water, applyingto said surface an acid resist, applying water to said surface todissolve sald medium and to re- .move said resist where it overlies saidmedium to expose the. surface of the plate, deep etching said exposedportions of the plate,

andfurther preparing said plate for printmg.

4. The process of making a printing plate which comprises sensitizingthe surface of the plate, exposing said surface to light action througha negative, developing said surface after it is exposed, a plying toparts of said surface by means 0 a brush a pigmentous medium soluble inwater, applying to said surface an'acid resist, a plying water to saidsurface to dissolve-sai medium and to remove said resist where itoverlies said medium to expose the surface of the plate, deep etchlngsaid exposed portions of the plate, and further preparing said plate forprinting. 5. The process of making a printin plate which comprisessensitizing the sur ace of the plate, exposing said surface to light,ac-

tionthrough a half tone negative, developing said surface after it isexposed, applying to parts of said surface by means of a brush amedium'soluble in a given solvent, applying to said developed surface anacid resist insoluble in said solvent, applying said solvent to dissolvesaid soluble medium and to remove said resist where it overlies saidmedium to expose the surface of the plate, deep etching said exposedportions of the plate, and applying a half tone etch to the surface ofsaid plate.

6. The process of making a printing plate which comprises sensitizingthe surface of the plate, exposing said surface to light action througha halftone negative, developing said surfaceafter it is exposed,applying to parts of said surface by means of a brush a medium solublein water, applying to said surface an acid resist, applying Water tosaid surface to dissolve said medium and to remove said resist where itoverlies said medium to expose the surface of the plate, deep etchingsaid exposed portions of the plate, and applying a half tone etch to thesurface of said plate.

7. The process of making a printing plate which comprises sensitizingthe surface of the plate, exposing said surface to light action througha negative, developing said surface after it is exposed, applying toparts of said surface by a medium soluble in a given solvent, applyingto said developed surface an acid resist soluble in said solvent,applying said solvent to dissolve said soluble medium and to remove saidresist where it overlies said medium to expose the surface of the plate,deep etching said exposed portions of the plate, and furtherpreparingsaid plate for printing.

8. The process of making a printing plate which comprises sensitizingthe surface of the plate, exposing said surface to light action througha negative, developing said surface after it is exposed, applying toparts of said surface a medium soluble in water, applying to saidsurface an acid resist, applying water to said surface to dissolve saidmedium and to remove said resist where it overlies said medium to exposethe surface of the plate, deep etching said exposed portions of theplate, and further preparing said plate for printing.

9. The process of making a printing plate which comprises sensitizingthe surface of .the plate, exposing said surface to light action througha half tone negative, developing said surface after it is exposed, ap-

plying to parts of said surface a medium"- soluble in water, applying tosaid surface an acid resist, applying water to said surface to dissolvesaid medium and to remove said resist where it overlies said medium toexpose the surface of the plate, deep etching said exposed portions ofthe plate, and applying a half tone etch to the surface of said plate.

10. The process of producing a printing plate which comprisessensitizing the surface of the plate, exposing said sensitized I tionsof the plate surface so exposed, and

preparing the surface of saidplate for printing.

11. The process of producing a printing plate which comprisessensitizing the surface of the plate, exposing said sensitized surfaceto the action of light through a design impression instrumentality,developing said exposed surface, applying manually to portionsof saidsurface after development a soluble pigmentous layer, applying to saidsurface a layer of acid resistant material, dissolving said solublelayer and thus removing therewith the overlying part of said acid.resistant material, deep etching the portions of the plate so exposed,removing the acid resistant material, and preparing the surface of saidplate for printing.

12. The process of making a half tone copper plate which comprisessensitizing the surface of the plate, exposing said surface to lightaction through a half tone negative, developing said exposed surface,applying to parts of said surface bymeans of a brush,

a pigmentous aqueously soluble medium, applying to said developedsurface of the plate an acid resistant insoluble in water, applyingwater to the surface of the plate to rembve said aqueously solublemedium and the portion of the resist overlying the same, deep etchingthe parts of the plate thus exposed, and removing the resist andapplying a half tone etch to the surface of the plate.

In testimony whereof, I have signed my name to this specification, inthe presence of two subscribing witnesses.

EMIL LEITNER.

Witnesses JOHN D. MoRoAN, Aucusrm J. Powers.

